3. A two-stage cascade vapor-compression refrigeration system uses R-12 produces 15 tons of refrigeration. A direct-contact heat exchanger is the cascade condenser. The low temperature evaporator pressure is 100 kPa, and the condenser pressure is 1000 kPa. The intermediate pressure is optimum. Determine (a) the mass flow rate in the upper and lower stages, (b) the total input power for the compressors, and (c) the COP.

3. A two-stage cascade vapor-compression refrigeration system uses R-12 produces 15 tons of refrigeration. A direct-contact heat exchanger is the cascade condenser. The low temperature evaporator pressure is 100 kPa, and the condenser pressure is 1000 kPa. The intermediate pressure is optimum. Determine (a) the mass flow rate in the upper and lower stages, (b) the total input power for the compressors, and (c) the COP.

Refrigeration and Air Conditioning Technology (MindTap Course List)

8th Edition

ISBN:9781305578296

Author:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Publisher:John Tomczyk, Eugene Silberstein, Bill Whitman, Bill Johnson

Chapter47: High-pressure, Low-pressure, And Absorption Chilled-water Systems

Section: Chapter Questions

Problem 13RQ: The subcooling temperature in a condenser can be measured by taking the difference between the A....

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